“The summer (June through August) temperature reconstruction, extending back to 1038 CE, exhibits three warm periods in 1040–1190 CE, 1370–1570 CE and the 20th century and one extended cold period between 1570 and 1920 CE.”

“The Global Historical Climatology Network (GHCN) v2 temperature time series (GISS Surface Temperature Analysis, 2012) in Alice Spring and all the 36 other stations located in a circle of 1,000 km from Alice Spring do not show any warming. There are stations covering different time windows having very close patterns of temperatures. In this circle of 3,141,593 km2 (roughly 50% of Australia) that is mostly underdeveloped, none of the stations […] has a warming trend. … It is therefore only an artefact by BOM to produce the warming. Homogenization is supposed to be used to account for upwards biases such as Urban Heat Island, not to introduce upwards biases. … In the centre of Australia, all the stations available in a circle of radius 1,000 km were showing very little or no warming, as still acknowledged in the GHCN v2 data set up to October 2011 (Fig. 6). … Table 1 presents the warming trend for the 30 longest temperature records of Australia collected in a single location, with measurements started before 1900 and continued until after 1985. … In the 30 locations, the monthly mean maximum temperature is warming 0.0004°C/year, or0.04°C/century. That means there is no change within the limits of accuracy of the measurements. … The climate trend maps compiled by Bureau of Meteorology in their climate change section are completely unreliable, as the alleged increasing temperature is obtained by lowering temperatures of the past by “adjustments”. The longest of the Australian temperature records that were considered the most reliable by Bureau of Meteorology on February 2009 (BOM 2009) are still available as raw temperatures in the climate data online section and consistently show no warming and no increased extreme events within the limit of accuracy of measurements.”

“Spanning the period 1186-2014 CE, the new reconstruction reveals overall warmer conditions around 1200 and 1400, and again after ~1850. … Little agreement is found with climate model simulations that consistently overestimate recent summer warming and underestimate pre-industrial temperature changes. … [W]hen it comes to disentangling natural variability from anthropogenically affected variability the vast majority of the instrumental record may be biased. …

“The transition from warm to colder climatic conditions occurs around 1300 CE associated with the Wolf solar minimum. The coldest SSTs are detected between 1350 and 1850 CE, on Iberia during the well-known Little Ice Age (LIA) (Bradley and Jones, 1993), with the most intense cooling episodes related with other solar minima events, and major volcanic forcing and separated by intervals of relative warmth (e.g. (Crowley and Unterman, 2013; Solanki et al., 2004; Steinhilber et al., 2012; Turner et al., 2016; Usoskin et al., 2011). During the 20th century, the southern records show unusually large decadal scale SST oscillations in the context of the last 2 millennia, in particular after the mid 1970’s, within the Great Solar Maximum (1940 – 2000 (Usoskin et al., 2011)) and the “greater salinity anomaly” event in the northern Atlantic (Dickson et al., 1988), or yet the higher global temperatures of the last 1.4 ky detected by (Ahmed et al., 2013).”

“The results indicate that the climate of the Medieval Climate Anomaly (MCA, AD 900–1300) was similar to that of the Current Warm Period (CWP, AD 1850–present) … As for the Little Ice Age (LIA, AD 1550–1850), the results from this study, together with previous data from the Makassar Strait, indicate a cold and wet period compared with the CWP and the MCA in the western Pacific. The cold LIA period agrees with the timing of the Maunder sunspot minimum and is therefore associated with low solar activity.”

“This paper presents new high-resolution proxies and paleoclimatic reconstructions for studying climate changes in China for the past 2000 years. Multi-proxy synthesized reconstructions show that temperature variation in China has exhibited significant 50–70-yr, 100–120-yr, and 200–250-yr cycles. Results also show that the amplitudes of decadal and centennial temperature variation were 1.3◦C and 0.7◦C, respectively, with the latter significantly correlated with long-term changes in solar radiation, especially cold periods, which correspond approximately to sunspot minima. The most rapid warming in China occurred over AD 1870–2000, at a rate of 0.56◦ ± 0.42◦C (100 yr)−1; however, temperatures recorded in the 20th century may not be unprecedented for the last 2000 years, as data show records for the periods AD 981–1100 and AD 1201–70 are comparable to the present.”

“Reconstructed SSTs significantly warmed 1.1°C … from 1660s to 1800 (rate of change: 0.008°C/year), followed by a significant cooling of 0.8°C … until 1840 (rate of change: 0.02°C/year), then a significant warming of 0.8°C from 1860 until the end of reconstruction in 2007 (rate of change: 0.005°C/year).” [The amplitude of sea surface temperature warming and cooling was higher and more rapid from 1660s-1800 than from 1860-2007.]

‘In fact, the SST reconstruction significantly co-varied with a reconstruction of solar irradiance [Lean, 2000] on the 11-year periodicity only from ~1745 to 1825. In addition, the reconstructed SSTs were cool during the period of lower than usual solar irradiance called the Maunder minimum (1645–1715) but then warmed and cooled during the Dalton minimum (1795–1830), a second period of reduced solar irradiance. … The Dalton solar minimum and increased volcanic activity in the early 1800s could explain the decreasing SSTs from 1800 to 1850.”

“A recent effort to characterize Antarctic and sub-Antarctic climate variability during the last 200 years also concluded that most of the trends observed since satellite climate monitoring began in 1979 CE cannot yet be distinguished from natural (unforced) climate variability (Jones et al., 2016), and are of the opposite sign [cooling, not warming] to those produced by most forced climate model simulations over the same post-1979 CE interval. … (1) Temperatures over the Antarctic continent show an overall cooling trend during the period from 0 to 1900CE, which appears strongest in West Antarctica, and (2) no continent-scale warming of Antarctic temperature is evident in the last century.”

“After the 8.2 ka event, Greenland temperature reached the Holocene thermal maximum with the warmest decades occurring during the Holocene (2.9 ± 1.4 °C warmer than the recent decades) at 7960 ± 30 years B.P. … For the most recent 10 years (2005 to 2015), apart from the anomalously warm year of 2010, mean annual temperatures at the Summit exhibit a slightly decreasing trend in accordance with northern North Atlantic-wide cooling. The Summit temperatures are well correlated with southwest coastal records (Ilulissat, Kangerlussuaq, Nuuk, and Qaqortoq).”

“For the most recent 10 years (2005 to 2015), apart from the anomalously warm year of 2010, mean annual temperatures at the Summit exhibit a slightly decreasing trend in accordance with northern North Atlantic-wide cooling. The Summit temperatures are well correlated with southwest coastal records (Ilulissat, Kangerlussuaq, Nuuk, and Qaqortoq).”

“Our analyses reveal appreciable and stable positive correlation between summer temperatures in Northern Fennoscandia and sea surface temperature in North Atlantic over AD 1567–1986. Thus a connection between climates of Northern Fennoscandia and North Atlantic basin is established for more than the last four centuries. Significant correlation was found between SST [sea surface temperatures] in NA [the North Atlantic] and solar activity (both instrumental data and proxies) during AD 1716–1986. … Thus, the connection between Northern Fennoscandian climate and solar activity, which has been previously established at century-scale (Ogurtsov et al., 2001, 2002, 2013) and millennial-scale (Helama et al., 2010), is confirmed for AD 1716–1986 over the entire frequency range using unfiltered records (with the exception for AMO reconstruction after Mann et al. (2009)).”

“The highest δ18O [temperature proxy] value of the record occurs at ca. 1900–1800 cal. yr BP (~50–150 CE), coinciding with a period of general warmth referred to as the Roman Warm Period (RWP). In the North Atlantic Ocean, the RWP interval (ca. 2500–1500 cal. yr BP) is associated with, for example, increased temperatures and productivity, decreased evidence of ice … Northern Hemisphere terrestrial environments widely display evidence of elevated temperatures between 1 and 300 CE (Ljungqvist, 2010). … southern Spitsbergen experienced a significant late-Holocene cold spell prior to the onset of the LIA [Little Ice Age]. These negative shifts overlap with the latter part of a cooling known as the Dark Ages Cold Period (DACP, ca. 1500–1000 cal. yr BP; Bianchi and McCave, 1999; McDermott et al., 2001). Theevent is directly preceded by a minimum in total solar irradiation (Renssen et al., 2006; Steinhilber et al., 2009) … A wealth of proxy evidence testifies to the LIA [Little Ice Age] cooling, thought to have been triggered by reduced solar irradiance, extended volcanism, and internal characteristics of the ocean–atmosphere system (Miller et al., 2010, 2012; Wanner et al., 2011). … Factoring in respective age-model uncertainties, it appears that all major negative shifts, that is, ‘cold’ periods, in the δ18Olw record are roughly synchronous with periods of major negative anomalies in total solar irradiation and high modeled probabilities for extremely cold years in the Nordic Seas (Renssen et al., 2006), and widespread evidence of North Atlantic ‘cold spells’ (Bond et al., 2001; Sarnthein et al., 2003; Solomina et al., 2015; Wanner et al., 2008) linked to solar forcing.”

“Occupying about 14% of the world’s surface, the Southern Ocean plays a fundamental role in ocean and atmosphere circulation, carbon cycling and Antarctic ice-sheet dynamics. … As a result of anomalies in the overlying wind, the surrounding waters are strongly influenced by variations in northward Ekman transport of cold fresh subantarctic surface water and anomalous fluxes of sensible and latent heat at the atmosphere–ocean interface. Thishas produced a cooling trend since 1979.”

“[T]he recent summer-time warming in Scotland is likely not unique when compared to multi-decadal warm periods observed in the 1300s, 1500s, and 1730s“

“Here we review proxy records of intermediate water temperatures from sediment cores and corals in the equatorial Pacific and northeastern Atlantic Oceans, spanning 10,000 years beyond the instrumental record. These records suggests that intermediate waters [0-700 m] were 1.5-2°C warmer during the Holocene Thermal Maximum than in the last century. Intermediate water masses cooled by 0.9°C from the Medieval Climate Anomaly to the Little Ice Age. These changes are significantly larger than the temperature anomalies documented in the instrumental record. The implied large perturbations in OHC and Earth’s energy budget are at odds with very small radiative forcing anomalies throughout the Holocene and Common Era. … The records suggest that dynamic processes provide an efficient mechanism to amplify small changes in insolation [surface solar radiation] into relatively large changes in OHC.”

“We suggest that solar activity may play a key role in driving the climatic fluctuations in NC [North China] during the last 22 centuries, with its quasi ∼100, 50, 23, or 22-year periodicity clearly identified in our climatic reconstructions. … It has been widely suggested from both climate modeling and observation data that solar activity plays a key role in driving late Holocene climatic fluctuations by triggering global temperature variability and atmospheric dynamical circulation“

“Our sortable-silt time series show prominent multi-decadal to multi-centennial variability, but no clear long-term trend over the past 4200 years. … [O]ur findings indicate that variations in the strength of the main branch of the Atlantic Inflow may not necessarily translate into proportional changes in northward oceanic heat transport in the eastern Nordic Seas.”

“2003– 2009 was the warmest period in the reconstruction. 1970– 2000 was colder than the last stage of the Little Ice Age (LIA).”

“The reconstruction is punctuated by a temperature increase during the 20th century; yet extreme cold and warm events during the 19th century seem to eclipse conditions during the 20th century. We found significant correlations between our March–April spring temperature reconstruction and existing gridded spring temperature reconstructions for Europe over Turkey and southeastern Europe. … During the last 200 years, our reconstruction suggests that the coldest year was 1898 and the warmest year was 1873. The reconstructed extreme events also coincided with accounts from historical records. … Further, the warming trends seen in our record agrees with data presented by Turkes and Sumer (2004), of which they attributed [20th century warming] to increased urbanization in Turkey.”

“The early part of the reconstruction (1733–1850) coincides with the end of the Little Ice Age, and exhibits 3 of the 4 coolest decadal excursions in the record. However, the mean SST estimate from that interval during the LIA is not significantly different from the late 20th Century SST mean. The most prominent cooling event in the 20th Century is a decade centered around 1965. This corresponds to a basin-wide cooling in the North Atlantic and cool phase of the AMO.”

“Through several idealized and real proxy experiments we assess the spatial and temporal extent to which isotope records can reconstruct surface temperature, 500 hPa geopotential height, and precipitation. We find local reconstruction skill to be most robust across the reconstructions, particularly for temperature and geopotential height, as well as limited non-local skill in the tropics. These results are in agreement with long-held views that isotopes in ice cores have clear value as local climate proxies, particularly for temperature and atmospheric circulation.”

“Shallow marine molluscs that are today extinct close to Svalbard, because of the cold climate, are found in deposits there dating to the early Holocene. The most warmth-demanding species found, Zirfaea crispata, currently has a northern limit 1000 km farther south, indicating that August temperatures on Svalbard were 6°C warmer at around 10.2–9.2 cal. ka BP, when this species lived there. … After 8.2 cal. ka, the climate around Svalbard warmed again, and although it did not reach the same peak in temperatures as prior to 9 ka, it was nevertheless some 4°C warmer than present between 8.2 and 6 cal. ka BP. Thereafter, a gradual cooling brought temperatures to the present level at about 4.5 cal. ka BP. The warm early-Holocene climate around Svalbard was driven primarily by higher insolation and greater influx of warm Atlantic Water, but feedback processes further influenced the regional climate.”

“This paper presents a multi proxy lake record of NW Greenland Holocene climate. … Summer temperatures (2.5–4 °C warmer than present) persisted until ∼4 ka [4,000 years ago] … Continual cooling after 4 ka led to coldest temperatures after 1.2 ka, with temperature anomalies 2-3°C below present. Approximately 1000 km to the south, a 2-3°C July temperature anomaly (relative to [warmer than] present) between 6 and 5 ka was reported based upon chironomid assemblages near Illulisat and Jakobshavn (Axford et al., 2013). Across Baffin Bay on northeastern Baffin Island, HTM summer temperatures were an estimated ~5°C warmer than the pre-industrial late Holocene and 3.5°C warmer than present, based upon chironomid assemblages (Axford et al., 2009; Thomas et al., 2007). … Following deglaciation, the GrIS [Greenland Ice Sheet] retreated behind its present margins (by as much as 20-60 km in some parts of Greenland) during the HTM [Holocene Thermal Maximum] (Larsen et al., 2015; Young and Briner, 2015).”

“The chironomid-based record from Heihai Lake shows a summer temperature fluctuation within 2.4°C in the last c. 5000 years from the south-east margin of the QTP [Qinghai–Tibetan Plateau]. … The summer temperature changes in this region respond primarily to the variation in the Asian Summer Monsoon. The variability of solar activity is likely an important driver of summer temperatures, either directly or by modifying the strength and intensity of the Indian Ocean Summer Monsoon. … We observed a relatively long-lasting summer cooling episode (c. 0.8°C lower than the 5000-year average) between c. 270 cal. BP and AD c. 1956. … The record shows cooling episodes occurred at c. 3100, 2600, 2100 and 1600 cal. BP. This is likely related to the period defined as the Northern Hemisphere Little Ice Age (LIA; c. AD 1350–1850, equivalent to 600–100 cal. BP). These possibly relate to the 500-year quasi-periodic solar cycle. Cooling stages between c. 270 and 100 cal. BP were also recorded and these are possibly linked to the LIA suggesting a hemisphere-wide forcing mechanism for this event.”

“Growing paleoclimatic evidence suggests that the climatic signals of Medieval Warm Period and the Little Ice Age events can be detected around the world (Mayewski et al., 2004; Bertler et al., 2011). … [T]he causes for these events are still debated between changes in solar output, increased volcanic activity, shifts in zonal wind distribution, and changes in the meridional overturning circulation (Crowley, 2000; Hunt, 2006).”

“Overall, the strong linkage between solar variability and summer SSTs is not only of regional significance, but is also consistent over the entire North Atlantic region.”

“The last ca. 1000 years recorded the warmest SST averaging 28.5°C. We record, for the first time in this region, a cool interval, ca. 1000 years in duration, centered on 5000 cal years BP concomitant with a wet period recorded in Borneo. The record also reflects a warm interval from ca. 1000 to 500 cal years BP that may represent the Medieval Climate Anomaly. Variations in the East Asian Monsoon (EAM) and solar activity are considered as potential drivers of SST trends. However, hydrology changes related to the El Nino-Southern Oscillation (ENSO) variability, ~ shifts of the Western Pacific Warm Pool and migration of the Intertropical Convergence Zone are more likely to have impacted our SST temporal trend. … The SA [solar activity] trends (Steinhilber et al., 2012) are in general agreement with the regional cooling of SST (Linsley et al., 2010) and the SA [solar activity] oscillations are roughly coincident with the major excursions in our SST data.”

“Representing one of the strongest global climate instabilities during the Holocene, the Little Ice Age (LIA) is marked by a multicentennial-long cooling (14-19th centuries AD) that preceded the recent ‘global warming’ of the 20th century. The cooling has been predominantly attributed to reduced solar activity and was particularly pronounced during the 1645-1715 AD and 1790-1830 AD solar minima, which are known as Maunder and Dalton Minima, respectively.”

“The SST [sea surface temperature] shows a broad maximum (~17.3 °C) in the mid-Holocene (5-7 cal kyr BP), which corresponds to the Jomon transgression. … The SST maximum continued for only a century and then the SST [sea surface temperatures] dropped by 3.5 °C [15.1 to 11.6 °C] within two centuries. Several peaks fluctuate by 2°C over a few centuries.”

“Our findings are generally consistent with other records from the ISM [Indian Summer Monsoon] region, and suggest that the monsoon intensity is primarily controlled by solar irradiance on a centennial time scale. This external forcing may have been amplified by cooling events in the North Atlantic and by ENSO activity in the eastern tropical Pacific, which shifted the ITCZ further southwards.”

“The existence of depressed MAAT [mean annual temperatures] (1.3°C lower than the 3200-year average) between 1480 CE and 1860 CE (470–90 cal. yr BP) may reflect the manifestation of the ‘Little Ice Age’ (LIA) in southern Costa Rica. Evidence of low-latitude cooling and drought during the ‘LIA’ has been documented at several sites in the circum-Caribbeanand from the tropical Andes, where ice cores suggest marked cooling between 1400 CE and 1900 CE. Lake and marine records recovered from study sites in the southern hemisphere also indicate the occurrence of ‘LIA’ cooling. High atmospheric aerosol concentrations, resulting from several large volcanic eruptions and sea-ice/ocean feedbacks, have been implicated as the drivers responsible for the ‘LIA’.”

“Late Holocene climate change in coastal East Asia was likely driven by ENSO variation. Our tree pollen index of warmness (TPIW) shows important late Holocene cold events associated with low sunspot periods such as Oort, Wolf, Spörer, and Maunder Minimum. Comparisons among standard Z-scores of filtered TPIW, ΔTSI, and other paleoclimate records from central and northeastern China, off the coast of northern Japan, southern Philippines, and Peru all demonstrate significant relationships [between solar activity and climate]. This suggests that solar activity drove Holocene variations in both East Asian Monsoon (EAM) and El Niño Southern Oscillation (ENSO).”

“The application of transfer functions resulted in reconstructed T July fluctuations of approximately 3 °C over the last 2800 years. Low temperatures (11.0-12.0 °C) were reconstructed for the periods between ca 1700 and 1500 cal yr BP (corresponding to the Kofun cold stage) and between ca 1200 and 150 cal yr BP (partly corresponding to the Little Ice Age [LIA]). Warmperiods (modern T[emperatures] July or higher) were reconstructed for the periods between ca 2700 and 1800 cal yr BP, 1500 and 1300 cal yr BP and after 150 cal yr BP.”

“[P]roxy-inferred annual MATs[annual mean air temperatures] show the lowest value at 11,510 yr BP (7.6°C). Subsequently, temperatures rise to 10.7°C at 9540 yr BP followed by an overall decline of about 2.5°C until present (8.3°C).”

“Contrary to the often-documented warming trend over the past few centuries, but consistent with temperature record from the northern Tibetan Plateau, our data show a gradual decreasing trend of 0.3 °C in mean annual air temperature from 1750 to 1970 CE. This result suggests a gradual cooling trend in some high altitude regions over this interval, which could provide a new explanation for the observed decreasing Asian summer monsoon. In addition, our data indicate an abruptly increased interannual-to decadal-scale temperature variations of 0.8 – 2.2 °C after 1970 CE, in terms of both magnitude and frequency, indicating that the climate system in high altitude regions would become more unstable under current global warming.”

“Conclusion: Using a multi-proxy approach, we studied the dynamics of thermokarst characteristics in western Latvia, where thermokarst occurred exceptionally late at the Holocene Thermal Maximum. … [A] thermokarst active phase … began 8500 cal. yr BP and lasted at least until 7400 cal. yr BP. Given that thermokarst arise when the mean summer air temperature gradually increased ca. 2°C beyond the modern day temperature, we can argue that before that point, the local geomorphological conditions at the study site must have been exceptional to secure ice-block from the surficial landscape transformation and environmental processes.”

“During the Middle Holocene we detect important climatic events. From 7000 to 6800 [years before present] (MIR 23 and MIR22), we register climatic characteristics that could be related to the end of the African Humid Period, namely an increase in temperatures and a progressive reduction in arboreal cover as a result of a decrease in precipitation. The temperatures exceeded current levels by 1°C, especially in MIR23, where the most highly represented taxon is a thermo-Mediterranean species, M. (T.)duodecimcostatus.”

“The small increase in global average temperature observed over the last 166 years is the random variation of a centrally biased random walk. It is a red noise fluctuation. It is not significant, it is not a trend and it is not likely to continue.”

“Reconstructions for southern Norway based on pollen and chironomids suggest that summer temperatures were up to 2 °C higher than present in the period between 8000 and 4000 BP, when solar insolation was higher (Nesje and Dahl, 1991; Bjune et al., 2005; Velle et al., 2005a).”

“Our study provides an estimate for the value of MAT of HTM of Pannon region with an interval of 0.4°C, relying on macroecological considerations. We calculate the temperature of the HTM [Holocene Thermal Maximum] 1.3–1.7°C warmer than the present temperature.”

“The lack of glacio-lacustrine sediments throughout most of the record suggests that the ice cap was similar to or smaller than present throughout most of the Holocene. This restricted ice extent suggests that climate was similar to or warmer than present, in keeping with other records from Greenland that indicate a warm early and middle Holocene. Middle Holocene magnetic susceptibility oscillations, with a ~200-year frequency in one of the lakes, may relate to solar influence on local catchment processes. … Air temperatures in Milne Land, west of our study area, based on preliminary estimates from chironomids, may have been 3–6°C warmer than at present (Axford et al. 2013), and in Scoresby Sund itself, warm ocean fauna, including Mytilus edulis and Chlamys islandica, both of which live far to the south today, occupied the fjords (Sugden and John 1965; Hjort and Funder 1974; Street 1977; Funder 1978; Bennike and Wagner 2013; Fig. 13). … Recession of Istorvet ice cap in the last decade has revealed plant remains that show that the glacier was smaller than at present during the early stages of the Medieval Warm Period, but expanded during the late Holocene ca. AD 1150 (Lowell et al. 2013).”

“According to the pollen records in the HRYR [Headwater Region of the Yellow River], the climate in the Holocene thermal maximum was warmer and wetter than present (temperature was 2 -3 °C higher than present)“

“[T]he reconstruction…shows that recent warming (until AD 2009) is not exceptional in the context of the past century. For example, the periods around AD 1940 and from AD 1950–1955 were warmer. This is also shown in the reanalysis data for this region and was also observed by Neukom et al. (2010b) and Neukom and Gergis (2011) for Patagonia and central Chile. Similarly, based on tree ring analyses from the upper tree limit in northern Patagonia, Villalba et al. (2003) found thatthe period just before AD 1950 was substantially warmer than more recent decades.”

“[W]e should point out that the rapid warming during the 20th century was not especially obvious in our reconstructed RLST [surface temperatures].”

“[P]resent-day global mean air temperatures may have been equally high around 1000 years ago during the so-called Medieval Climate Anomaly (MCA; Lamb, 1969; Grove and Switsur, 1994). However, since regional temperature reconstructions display large variability in the timing and magnitude of the MCA (PAGES 2k Consortium, 2013), this issue has not yet been adequately settled. Hence, there is still a great need to produce and improve empirical proxy data to further our understanding of near and distant climate changes.”

“[O]ur results indicate that Karakorum temperature has remained decidedly out of phase with hemispheric temperature trends for at the least the past five centuries”

“Absence of 21st century warming on Antarctic Peninsula consistent with natural variability”

“Analysis of climate data for SE Iceland also indicates that the three periods of ice-frontal retreat [1936-’41, 1951-’56, and 2006-’11] identified are associated with similar summer air temperature values, which has previously been shown to be a key control in terminus variations in Iceland. We, therefore, demonstrated that the coincidence of the most recent phase of ice-frontal retreat at Skálafellsjökull (2006–2011) and warming summer temperatures is not unusual in the context of the last ~80 years. This highlights the need to place observations of contemporary glacier change in a broader, longer-term (centennial) context.”

“[C]limate model simulations that include anthropogenic forcing are not compatible with the observed trends. … Over the 36-year satellite era, significant linear trends in annual mean sea-ice extent, surface temperature and sea-level pressure are superimposed on large interannual to decadal variability. Most observed trends, however, are not unusual when compared with Antarctic palaeoclimate records of the past two centuries.”

“We identified four major cold periods (1839–1846, 1884–1901, 1906–1908 and 1941–1958) and three major warm periods (1855–1880, 1918–1932 and 1998–2013) in the past 211 years. The multi-taper method spectral analysis revealed significant cycles at 48.8, 11.5, 8.9, 3.9, 3.5 and 2–3 years, which might be associated with global climate oscillations and land-sea thermal contrasts, such as the sea surface temperatures, El Niño-Southern Oscillation, Atlantic Multidecadal Oscillation and solar activity.”

“We determined that temperatures for the ablation measurement periods in late July to early September were similar in both 1933 and the recent period [1990s – present], indicating that the temperature forcing of ablation within the early warm period and the present are similar.”

“Solar activity modulates patterns in surface temperature and pressure that resemble NAO phases, through dynamical coupling processes between the stratosphere and the troposphere that transmit the solar signal to the Earth’s surface.”

“The very fast climate warming of the Euro-Asian continent that began in the 1970s may be associated with the enhanced heat transport from the North Atlantic in this period. This is evident from the fields and time series obtained in the present paper. The hiatus of this warming after 1999 may be due to the decreased heat transfer from the North Atlantic Ocean to the Eurasian territory.”

“We calibrate individual robust Sr / Ca records with in situ SST and various gridded SST products. The results show that the SST record from Cabri provides the first Indian Ocean coral proxy time series that records the SST signature of the PDO in the south-central Indian Ocean since 1945. … Marked negative Sr /Ca anomalies (warmer) are observed during the first half of the 20th century centred at 1918/19, 1936–1941 and in the period 1948–1951 that exceed anomalies in the 1961 to 1990 reference period.”

“The time frame is 1883-2014. … Varying the parameters of the construction methodology creates 333 time series with a central trend-value based on the largest group of stations of -0.07 °C decade-1 with a best-guess estimate of measurement uncertainty being -0.12 to -0.02 °C decade-1. This best-guess result is insignificantly different (0.01 C decade-1) from a similar regional calculation using NOAA nClimDiv data beginning in 1895. … Finally, 77 CMIP-5 climate model runs are examined for Alabama and indicate no skill at replicating long-term temperature and precipitation changes since 1895.”

“We conclude that at our study sites annual net ablation is likely to be larger in recent years than during any previous period in the instrumental era, covering up to 150 years. … [I]n southern Greenland ablation peaked significantly around 1930. While most of Greenland underwent relatively warm (summer) conditions in the 1930s (Cappelen 2015), this was most notable at the more southern locations, resulting in amplified ablation values according to our estimates. JJA [summer] temperatures were higher in 1928 and 1929 than in any other year of the Qaqortoq record, both attaining values of 9.2°C. This suggests that ablation in those years may have exceeded the largest net ablation measured on the Greenland ice sheet ( 2010).”

“Distal lakes document rapid early Holocene deglaciation from the coast and across the highlands south of the glacier. Sediment from Skorarvatn, a lake to the north of Drangajokull, shows that the northern margin of the ice cap reached a size comparable to its contemporary limit by ~10.3 ka. Two southeastern lakes with catchments extending well beneath modern Drangajokull confirm that by ~9.2 ka, the ice cap was reduced to ~20% of its current area.”

“[R]ecent air temperatures (1993–2003) are, on average, 0.5 °C lower than air temperatures estimated during the MWP [Medieval Warm Period] and Holocene Climate Optimum. … [P]eriods warmer than modern periods occurred for ∼6.5 ka [6,500 years] including during the HCO and Medieval Warm Period.”

“Results of this study show that warm intervals over the last 2000 years were in AD 1-200, AD 551-760, AD 951-1320, and after AD 1921, while cold intervals were in AD 201-350, AD 441-530, AD 781-950, and AD 1321-1920. Interestingly, temperatures during AD 981-1100 and AD 1201-1270 were comparable to those of our Present Warm Period, but have an uncertainty of 0.28°-0.42°C at 95% confidence level. Temperature variations over the whole of China are typically in phase with those of the Northern Hemisphere (NH) after AD 1000, the period which covers the Medieval Climate Anomaly, the Little Ice Age (LIA), and the Present Warm Period.”

“The dominant warm and arid conditions during the MCA [Medieval Climate Anomaly, 900-1300 CE], and the cold and wet conditions during the LIA [Little Ice Age, 1300-1850 CE] indicate the interplay of the NAO+, EA+ and NAO- , EA- [positive/negative North Atlantic Oscillation, East Atlantic phases], respectively. Furthermore, the higher solar irradiance during the [“warm conditions”] RP [Roman Period, 200 BCE – 500 CE] and MCA [Medieval Climate Anomaly, 900-1300 CE] may support the predominance of the EA+ [positive East Atlantic] phase, whereas the opposite scenario [“colder temperatures”] during the EMA [Early Middle Age, 500-900 CE] and LIA [Little Ice Age, 1300-1850 CE] may support the predominance of the EA- [negative East Atlantic] phase, which would favour the occurrence of frequent and persistent blocking events in the Atlantic region during these periods.”

“Much of the North Atlantic shows a maximum between 5000-8000 years B.P. Bradley et. al (2003) compiled a number of marine and terrestrial paleoclimatic proxies from throughout the Holocene which show fairly consistent broad trends in the climatic history of the North Atlantic region. Drawing from isotopic concentrations in ice cores, diatoms, pollen, and dendrochronological analyses, a clear period of elevated temperature, beginning at about 10,000 B.P and concluding at about 6,000 B.P precedes a slow and steady trend of cooling until present day.”

“In addition to temperature records limited to the past 4000 years, data for the past few thousand years were tested. When the data were explored over the past 10,000 years, greater fluctuations in the temperature can be seen with a significant rise in temperature beginning at about 11,000 BCE and ending at 2000 CE with a maximum at about 5,000 BCE.”

“The major external forcing of the climate system derives from the Sun. A solar signature has been found in global mean surface temperatures, with evidence directly related to two noticeably different features of the Sun’s dynamics: its short-term irradiance fluctuations and secular patterns of 22-year and 11-year cycles (Scafetta and West, 2008). … [I]t is recognized that solar forcing manifestations denote a strong spatial and seasonal variability (Usoskin et al., 2006), and this would be the reason why it might be illusive to seek a single global relationship between climate and solar activity (de Jager, 2005). Thus, Le Mouël et al. (2009) stated that a regional approach may allow one to identify specific forms of solar forcing, where and when the solar input is most important. … [S]olar footprints on terrestrial temperatures [are] due to the strong non-linear hydrodynamic interactions across the Earth’s surface, and the accepted longerterm solar activity influence creating temperature oscillations for tens or even hundreds of years (Scafetta and West, 2003, 2007, 2008). … These spectral analysis results appear to support a solar forcing with regards to Minho GHD [grape harvest dates]”

“We suggest that deviations in ELA fluctuations between Scandinavian maritime and continental glaciers around 7150, 6560, 6000, 5150, 3200 and 2200 cal. yr BP reflect the different response of continental and maritime glaciers to drops in total solar irradiance (TSI).”

“A study of chironomid remains in the sediments of Lake JR01 on the Boothia Peninsula in the central Canadian Arctic provides a high-resolution record of mean July air temperatures for the last 6.9 ka …. Biological production decreased again at ~ 2 ka and the rate of cooling increased in the past 2 ka, with coolest temperatures occurring between 0.46 and 0.36 ka [460 and 360 years ago], coinciding with the Little Ice Age. Although biological production increased in the last 150 yr, the reconstructed temperatures do not indicate a warming during this time. … Modern inferred temperatures based on both pollen and chironomids are up to 3°C cooler than those inferred for the mid-Holocene.”

“The temperature decrease from the warmest to the coolest portions of the Holocene is 3.0 ± 1.0 °C on average (n = 11 sites). The Greenland Ice Sheet retracted to its minimum extent between 5 and 3 ka [5,000 and 3,000 years ago], consistent with many sites from around Greenland depicting a switch from warm to cool conditions around that time.”

“The temperature record, which integrates all seasons, shows rapid warming from the onset of the Holocene until ~9.5 ka [9,500 years ago], relatively uniform temperature at the millennial scale until ~7 ka [7,000 years ago], followed by ~3.5 °C temperature decline to the Little Ice Age [1250-1850 C.E.], followed by ~1.5 °C warming to today. [Today’s Greenland Ice Sheet temperatures are 2.0 °C colder than the Early and Middle Holocene] . The record also shows centennial-scale variability on the order of 1-2 °C, and a ~3 °C temperature oscillation during the 8.2 ka event.”

“[W]ithin the mid-LIG [Last Interglacial, ~125,000 years ago], a significantly higher than modern SST seasonality of 4.9°C (at 126 ka) and 4.1°C (at 124 ka) is observed. These findings are supported by climate model simulations and are consistent with the evolving amplitude of orbitally induced changes in seasonality of insolation throughout the LIG, irrespective of wider climatic instabilities that characterised this period.”

“The resulting Pw record is of higher resolution than previous reconstructions from glaciers in Norway and shows the potential of glacier records to provide high-resolution data reflecting past variations in hydroclimate. Complete deglaciation of the Ålfotbreen occurred ~9700 cal yr BP, and the ice cap was subsequently absent or very small until a short-lived glacier event is seen in the lake sediments ~8200 cal yr BP.The ice cap was most likely completely melted until a new glacier event occurred around ~5300 cal yr BP, coeval with the onset of the Neoglacial at several other glaciers in southwestern Norway. Ålfotbreen was thereafter absent (or very small) until the onset of the Neoglacial period ~1400 cal yr BP. The ‘Little Ice Age’ (LIA) ~650-50 cal yr BP [1350 to 1950] was the largest glacier advance of Ålfotbreen since deglaciation, with a maximum extent at ~400-200 cal yr BP, when the ELA was lowered approximately 200 m relative to today.”

“The climate was warmer and glaciers were likely receding in the beginning of the past millennium CE (the “Arkhyz break in glaciation”). … In this pass, remains of wood radiocarbon dated to 700 ± 80 BP (1180–1420 CE) were buried in a 1.5-m-thick layer of alluvium (Kaplin et al., 1971; Kotlyakov et al., 1973). Currently, the upper tree limit is located 800–900 m below this elevation. … According to indirect estimates based on pollen analyses, the upper tree limit in the “Arkhyz” period was 200–300 m higher than today (Tushinsky, Turmanina, 1979). The remains of ancient buildings and roads were also found in the Klukhorsky pass at an elevation of 2781 a.s.l. [above sea level] (Tushinsky et al., 1966), and the glacier was still present at this elevation in the mid 20th century. … [I]n Central and East Transcaucasia, there are artificial terraces at elevations where agriculture is not currently possible and that there are remnants of forests in places where forests have not grown since the 16th century CE.”

“Turmanina (1988), based on pollen analysis, suggested that, in the Elbrus area, the climate during the “Arkhyz” time was dryer and warmer than in the late 20th century by 1–2 °C. … Solomina et al. (2014) determined the Medieval warming in the Caucasus to be approximately 1 °C warmer than the mean of the past 4500 years. According to the Karakyol palynological and geochemical reconstructions, the warm period was long and lasted for five centuries. Considering the suggestion of Turmanina (1988) that it was also less humid, the likelihood that many glaciers, especially those located at relatively low elevation, disappeared is very high. … The maximum glacier extent in the past millennium was reached before 1598 CE. The advance of the 17th century CE, roughly corresponding to the Maunder Minimum, is recorded at Tsey Glacier. … General glacier retreat started in the late 1840s CE and four to five minor readvances occurred in the 1860s–1880s CE. In the 20th century CE, the continued retreat was interrupted by small readvances in the 1910s, 1920s and 1970s–1980s.”

“Together, the proxies suggest that the early Holocene experienced larger than average snowpacks but very warm summers. Warmer than modern summer temperatures were maintained through much of the mid-Holocene, but snowpacks decreased dramatically, creating the most extreme xeric conditions in the Holocene between ~7100 and 6000 BP.”

“[T]he interior of the GrIS [Greenland Ice Sheet] is flowing 95% slower now than it was on average during the Holocene [the last 9,000 years].”

“Comparing the climate between the mid-Holocene and present in the Xi’an area, the MAT [mean annual temperature] was about 1.1°C higher than today and the AP [annual precipitaion] was about 278 mm higher than today, similar to the modern climate of the Hanzhong area in the southern Qinling Mountains.”

“Around [9,500 years ago], pine suddenly established vertical belts of at least 200 m. These represent the highest pine-forests during the Holocene, ca. 210–170 m higher than today when corrected for land uplift. By this, summer temperatures at least 1–1.3°C warmer than today are indicated for the early Holocene thermal maximum around [8,500 to 9,500 years ago].”

“In the past 500 years, Greenland temperatures have fluctuated back and forth between warming and cooling about 40 times, with changes every 25–30 years. … Comparisons of the intensity and magnitude of past warming and cooling climate changes show that the global warming experienced during the past century pales into insignificance when compared to the magnitude of profound climate reversals over the past 25,000 years. At least three warming events were 20–24 times the magnitude of warming over the past century, and four were 6–9 times the magnitude of warming over the past century.”

“[M]ost of the temperature trends since at least 1881 can be explained in terms of solar variability, with atmospheric greenhouse gas concentrations providing at most a minor contribution.”

“[T]emperature in Central Asia and northern Hemisphere revert back towards cooling trends in the late twentieth century.”

“The DIRECT reconstruction reveals long-term cooling during the LIA [Little Ice Age, 1300-1900 AD] and considerable warming during the MCA [Medieval Climate Anomaly/Medieval Warm Period, 800-1200 AD]. The 20th century marks a period of generally warm temperatures; however, the temperatures of the MCA were reconstructed to be warmer and the long duration of the former makes the MCA incomparable to the 20th-century warmth (Matskovsky and Helama, 2014).”

“Southern Greenland proxy-inferred atmospheric temperatures also peaked between ca. 7 and 4 cal. kyr B.P. at2–4 °C higher than present, followed by a Neoglacial cooling reaching a minimum during the LIA [Little Ice Age] (Fréchette and de Vernal, 2009; D’Andrea et al., 2011; Axford et al., 2013). The second phase of ice retreat behind the present-day extent in southwest and south Greenland was from ca. 1.5 to 1 cal. kyr B.P.”

“Lake Qinghai also displays significant temperature oscillations in the past 3000 years, which may reflect an amplified response to volcanic and/or solar forcings [Stuiver et al., 1995]. The warm period peaking around 2 ka coincides with the Roman warm period, which is followed by cooling into the little ice age, peaking at about 500 years ago (Figure 2). The most distinct and unusual feature of Lake Qinghai summer temperature record is a temperature decrease of more than 4°C between 5 and 3.5 ka. Such temperature changes have not been observed in ice core records in Greenland and speleothem records in China and East Asia. Here we show, however, that this “unusual” feature is in fact prevalent in regional records.”

“The results suggested that the mean SSTs around AD 990 (±40) and AD 50 (±40) were 28.1 °C and 28.7 °C, 0.8 °C and 1.4 °C higher than that during AD 1994–2005, respectively. These records, together with the tree ring, lake sediment and literature records from the eastern China and northwest China, imply that the temperatures in recent decades do not seem to exceed the natural changes in MCA [Medieval Climate Anomaly], at least in eastern Asia from northwest China to northern SCS.”

“A very weak long-term [1993-2011] cooling is seen over the bulk of the rest of the ocean below that depth [2000 m], includingthe entirety of the Pacific and Indian Oceans, along with the eastern Atlantic basin.”

“Through the LH [Late Holocene], ocean temperatures [North Atlantic, Nordic Seas] are comparable to the present, but up to 1°C warmer“

“We show that water masses linked to North Pacific and Antarctic intermediate waters were warmer by 2.1°C and 1.5°C, respectively, during the middle Holocene Thermal Maximum than over the past century. Both water masses were ~0.9°C warmer during the Medieval Warm period than during the Little Ice Age and ~0.65° warmer than in recent decades.”

“According to Chylek et al. (2009), the Arctic warming from 1900 to 1940 proceeded at a significantly faster rate than the warming during the more recent decades and was highly correlated with the Atlantic Multi-decadal Oscillation (AMO) suggesting that the Arctic temperature variability is highly linked to the Atlantic Ocean thermohaline circulation at various temporal scales.”

“A marine sediment record from off the shore of the western Antarctic Peninsula also shows an early Holocene optimum during which surface ocean temperatures were determined to be 3.5°C higher than present. Other evidence suggests that the George VI ice shelf on the southwestern Antarctic Peninsula was absent during this early-Holocene warm interval but reformed in the mid Holocene.”

“Sea surface temperature [Arctic Ocean] between ∼ AD 1885–1935 are warmer by up to 3°C with respect to the average modern temperatureat the coring site. For the period ∼ AD 1887–1945, reconstructed sea ice cover values are on average 8.3 months per year which is 1.1 months per year lower than the modern values.”

“The reconstructed SSA [Southernmost South America] mean summer temperatures between 900 and 1350 are mostly above the 1901–1995 climatology. After 1350, we reconstruct a sharp transition to colder conditions, which last until approximately 1700. The summers in the eighteenth century are relatively warm with a subsequent cold relapse peaking around 1850. In the twentieth century, summer temperatures reach conditions similar to earlier warm periods.”

“Climate events worldwide, such as the MWP and LIA, were seen in a 2485-year temperature series. The largest amplitude and rate of temperature both occurred during the EJE [Eastern Jin Event (343–425 AD)], but not in the late 20th century. The millennium-scale cycle of solar activity determined the long-term temperature variation trends, while century-scale cycles controlled the amplitudes of temperature. Sunspot minimum events were associated with cold periods. The prediction results obtained using caterpillar-SSA showed that the temperature would increase until 2006 AD on the central-eastern Plateau, and then decrease until 2068 AD, and then increase again.”

“A prominent feature of this record is the ∼1°C warm anomaly that occurred between 1930 and 1950. … Carolina Slope SST does not exhibit the warming trend seen in the AMO since the 1970s suggesting that other factors also impact SST variability at our site.”

“Sea-surface temperature (SST) estimates suggest warmer conditions than present (anomaly∼+2 °C) averaging at 7 °C in summer until 300 cal. years BP, although cooling pulses are recorded around 1700, 1500, 1200 and 800 cal. years BP. The last 300 years were marked by a cooling from 7.6 to 3.5 °C and sea-ice cover increasing up to 7 months/yr. … From 2500 to 300 cal. years BP, SSTs were relatively high with mean values of about 2 °C and 7 °C in winter and summer, respectively. Warm phases are recorded around 1900, 1600, 1320, 1120 and 325 cal. years BP, with an optimum centered at 1320 cal. years BP. After 300 cal. years BP, SSTs were significantly lower with mean values of about 0 °C and 3.5–4 °C in winter and summer, respectively. … The record of sea-surface conditions from core JM04 indicates warmer winter SSTs during the last 2500 years than the modern average. The only exception is the interval spanning from 250 to 50 years BP, which is characterized by particularly low temperatures both in winter and summer.”

“The 1945–1974 period was the warmest 30-yr mean period of the 20th century. However, this warming, in the context of the past four centuries, appears well within the range of normal limits. The 30-yr mean temperature anomaly for 1662–1691 (0.19°C) exceeds in magnitude (although not significantly, p = 0.23) the 1945–1974 mean (0.05°C).”

“The climate of the interior of South Africa was around 1°C cooler in Little Ice Age [AD 1300 to 1800] and may have been over 3°C higher than at present during the extremes of the medieval warm period [AD 1000 to 1300]. … It was variable throughout the millennium, but considerably more so during the warming of the eleventh to thirteenth centuries. The lowest temperature events recorded during the Little Ice Age in South Africa are coeval with the Maunder and Sporer Minima in solar irradiance. The medieval warming is shown to have coincided with … the Medieval Maximum in solar radiation.”

“[O]ur spatial analysis of Antarctic meteorological data demonstrates a net cooling on the Antarctic continent between 1966 and 2000, particularly during summer and autumn.”

“This record is the longest yet produced for New Zealand and shows clear evidence for persistent above-average temperatures within the interval commonly assigned to the MWP [Medieval Warm Period]. Comparisons with selected temperature proxies from the Northern and Southern Hemispheres confirm that the MWP was highly variable in time and space. Regardless, the NewZealand temperature reconstruction supports the global occurrence of the MWP.”

“Analysis of new data for eight stations in coastal southern Greenland, 1958–2001, shows a significant cooling (trend-line change −1.29°C for the 44 years), as do sea-surface temperatures in the adjacent part of the Labrador Sea”

“Figure 1 [below] shows two early warm decadal fluctuations: one in the 1380s (0.72 °C) and one in the 1420s (0.57 °C), both above the 95th percentile. The warm period of the 1420s was followed by a cold period that lasted from the mid-1430s to the end of the 1450s (0.45 °C, under the 10th percentile). Our series also reveals particularly warm events, above the 90th percentile, in the 1520s and between the 1630s and the 1680s. These decades were as warm as the end of the twentieth century. The high-temperature event of 1680 was followed by a cooling, which culminated in the 1750s (under the 5th percentile) — the start of a long cool period that lasted until the 1970s.”

“March–September temperature was reconstructed for the past 249 years, which shows a warming trend from 1750s until approximately 1790, followed by cooling until 1810, then by a gradual warming trend extending to 1950, and a notable cold period continuing up to the present. No evidence of a consistent warming trend over the last century or two commonly appearing in higher latitudes was found in the present reconstruction”

“Temporal and spatial variability are analysed in Greenland instrumental temperature records from 24 coastal and three ice sheet locations. … The standard period 1961–90 was marked by 1–2°C statistically significant cooling.”

“Summer temperatures at Donard Lake [Canadian Arctic] over the past 1250 yrs averaged 2.9 °C. At the beginning of the 13th century, Donard Lake experienced one of the largest climatic transitions in over a millennium. Average summer temperatures rose rapidly by nearly 2 °C from 1195–1220 AD [+0.80 C per decade], ending in the warmest decade in the record (~4.3 °C).”

“The rate of warming in 1920– 1930 is the most spectacular as pointed out by Chylek et al. (2006). Finally, Greenland climate was colder around 1920 and, in the 1970s and 1980s. The temperature minimum (resp. maximum) seems to have occurred in 1992 after the Mont Pinatubo eruption (resp. in 1931). The warm summers of recent years (1998, 2003, 2005), associated with large melt extent areas (Fettweis et al., 2007), seem to be less warm than these of the 1930s, as also pointed out by Hanna et al. (2007). … The absolute minimum [surface mass balance] occurred around 1930 with a SMB anomaly near −300 km3 yr−1 . Secondary (minor) SMB minima appear to have occurred in 1950 and 1960, equalling the surface mass loss rates of the last few years (1998, 2003, 2006). … After the 1990s, the GrIS SMB decreases slowly to reach the negative anomalies of the last few years, although the summers of the 2000s were not exceptional compared to 70 yr ago“

“The highest temperature was 22.7°C which was recorded at 1.01 cal ka BP. … Cooling period from 0.85 cal. ka BP to present. SST declined obviously in this period, with the maximum decrease amplitude of 2℃. … No global climate warming due to the greenhouse effect since the Industrial Revolution occurs in the study area.”

“The paleoclimate modeled for Whitewing [Sierra Nevada, CA] during the Medieval period was significantly warmer and slightly drier than present. Medieval mean annual minimum temperature was warmer than current by 3.2°C. with large differences in winter (+3.5°C, January) and summer (+4.0°C, July). Mean annual maximum temperature was also greater in the Medieval period (+2.3°C), with greater differences in winter (+3.2°C, January) than summer (+2.6°C, July). Annual precipitation was less by 24 mm.”

“The most striking feature of the present reconstruction is the absence of any warming trend in the 20th century”

‘Long-term trends in the temperature reconstruction are indicative of a 125-year periodicity that may be linked to solar activity as reflected in radiocarbon and auroral records. The results indicate that both the warm intervals during the Medieval Warm Epoch (-A.D. 800 to 1200) and the cold intervals during the Little Ice Age (-A.D. 1200 to 1900) are closely associated with the 125-year [solar activity] period.”